Electronics Forum | Tue Sep 21 11:34:10 EDT 2004 | davef
Several things to check are: * Ask Multicore if their flux res and your conformal coat are compatible. Conformal coats and NC flux res are notorious for having compatibily issues. * Conformal coat a bare board to determine if there is there is enoug
Electronics Forum | Wed Nov 28 16:08:38 EST 2007 | jmelson
I've been using Xilinx TQFP's in the 44 and 144 lead sizes with no trouble. I don't even bake them before reflow and have never had any problem. The Xilinx parts are certainly NOT sensitive, I could not break one with my bare hands if I tried (I ha
Electronics Forum | Thu Mar 11 02:56:01 EST 2010 | grahamcooper22
Hi, blow holes / pin holes / holes in joints are usually a sign that there is excess moisture somewhere around the solder joint. Moisture can be in pcbs / components, so try drying them....a simple thing to do is pass a bare pcb throught your reflow
Electronics Forum | Thu Jun 29 12:07:09 EDT 2017 | georgetruitt
HOW THICK IS THE BOARD? IS THERE A LOT OF COPPER IN THE BOARD? DOES YOUR CUSTOMERS PROVIDE HEAT RELIEF IN THE BOARDS BARREL DESIGN THERE NEEDS TO BE PLENTY OF ROOM FOR LEADFREE SOLDER TO FLOW, DID YOU CHECK YOUR PIN(LEAD)TO HOLE (BARREL) RATIO? N
Electronics Forum | Tue Dec 09 09:46:31 EST 2008 | lazzara55
SMT-ypw: Do you have information about IPC D-35 for reference? B3: The D-35 is a subcommittee responsible for developing industry guidelines on the proper handling, shipping and storage of printed boards and printed board assemblies. Moisture is a ma
Electronics Forum | Thu Feb 14 20:24:07 EST 2002 | scott
My first reaction would be to run! FAST! Flex -- well, it... flexes... and isn't flat. While you assemble it, While you transport it, While it goes through the oven... SMT Connectors typically need to be held down during reflow. Fiducial types are
Electronics Forum | Tue Sep 21 11:39:41 EDT 2004 | pabloquintana
Conformal coat a bare board to determine if there > is there is enough surface free energy from your > solder mask to prevent dewetting. Sorry for my ignorance, but what is "enough surface free energy"? How do I determine that? >* Bake a board
Electronics Forum | Fri Dec 16 08:00:26 EST 2005 | jax
What you are most likely dealing with: Insufficient Pure Sn layer ( multiple causes ) Because elevated temperatures accelerate the diffusion process, the thickness of the Pure Sn layer will reduce during every thermal cycle... ( bakeing PCBs, S
Electronics Forum | Wed May 07 17:52:36 EDT 2008 | wayne123
I have these boards that are a four layer FR4 material, we had been running them for quite awhile with no trouble, and then they started delaminating, I checked my Reflow oven profile and I was barely hitting the temps required for our paste, we then
Electronics Forum | Fri Jul 16 17:39:33 EDT 2010 | deanm
It is a PCB design issue where the copper patterns are not balanced among the layers. Baking the boards in order to correct the warpage will not improve it. We've had a problem with one bare board in particular warping the same way from two differen
